The turbo raises the torque curve at low RPMs. What truck engine right now (gasoline engine) produces peak torque at 1800 RPM, and then starts to drop off?

The good thing about turbo engines is that they provide high amounts of torque throughout. The natural aspirated engine provides high torque at certain peaks, and usually less torque than the turbo version. So, taking your example above, remove the turbo from the equation, and you will find that your engine is producing 30 lb/ft of torque at 1000 RPM, then slowly builds up until it peaks at 70 lb/ft @ 6000 RPM, and then drop off again. You will be worse off without the turbo.

Of course you can have a bigger engine. Let's compare 2.0L LNF with its 260 lb/ft of torque from 1850 RPM all the way to 5000 or 5500 (or whatever it is). The 4.2L V6 in F150 also has 260 lb/ft of torque, but it arrives at much higher 3750 RPM. Since it's a naturally aspirated engine, it produces less at low RPMs, and the LNF provides more torque at lower PRMs than the bigger naturally aspirated V6.

 

Uh, so now we're not simply looking at replacing a ~5.0L V8 - the expectation is that a highly-turbocharged I4 can compete with a 7.3L turbodiesel? Yeah, I'm not about to make that claim.

However, you fail to see that the vast difference in peak crank speed between the two engines enables the I4 to use deeper gearing. Let's say that the I4 spins to 6K and your diesel goes to 3K; in this case, the I4 could use a gear reduction that's 2x greater than your diesel and achieve the same torque at the rear wheels! As I've been claiming, HP counts - if you've got HP, then you can gear down and get torque. There's a limit to this, of course (I'm not real excited about replacing my 375 HP 383 with a 750 HP Champ Car engine), but if we're reasonable, and if we're talking about automatics with good converters and a lot of ratios, then this idea of looking at flywheel torque is a bit outdated.

So then what does it matter if they have a turbo I4, some outdated runt of a V6, or a smallish V8? I'm honestly not sure which of these has the potential for the optimum fuel economy, but I'm happy to see that all the options are on the table (of course, given the choice, I'd pick a direct-injection turbo V8!).

No one is saying that they're taking away the larger V8s for half-ton trucks - it's just that the majority of half-ton customers probably aren't best-served with an engine like that. And for the guys that really do push their half-tons to the max, the upcoming turbodiesels may very well provide better performance and economy.

Once again, no one is looking to take that away, and the mere existance of a smaller engine option doesn't somehow degrade the capability of other trucks

But you know as well as I do that we can get power with a lot of torque at few RPMs, or a bit of torque at a lot of RPMs, and that fundamentally, gearing becomes the way that we manage to put either one down to the pavement at a useful speed.

European semis run with 30 metric ton GVW with around 260 HP. Ever get caught behind one on a long climb? Holy crap, it's painful.

Yep - and if I'm trying to accelerate up a grade, it's a time-dependant function, and thus a function of power, right?

And of course, simply maintaining a constant speed up a grade is still acceleration (this is a function of the sine of the slope times the gravitational force times the vehicle speed, assuming that the speed remains constant). Climbing a grade of 8% at a constant speed requires the same amount of power as accelerating at a rate of 0.08g on level ground. If we're trying to climb this grade at highway speeds of 50 MPH with a GVW of 15,000 lbs, then we need to be putting down 163 HP to the rear wheels simply to overcome gravity (not to mention whatever we're spending to overcome air resistance). You can have a 150 HP engine with 1000 lb-ft of torque, and you'd be screwed in this situation.

I'm guessing I'm not the target market for this vehicle, as my sig might indicate

Works for me, man Besides, I gotta get back to my test lab and do some dyno testing on motors - which, although being quite a bit less powerful than what we're discussing in this thread, do happen to work within the same laws of physics

 

First, Ecoboost is designed to run on regular.

Next.......... "supposedly" this engine will be in the regular cab only, with restrictions on towing. It will be for business's that need to haul things in the bed of a truck, and need a big bed = F150, and want good fuel economy.

Third, there is a F100 coming, that is a smaller, and lighter F150 type truck. Think '97-04 F150 size. It will run the Ecoboost 4cyl also.

Fourth, the is a completely redesigned, global Ranger coming. It will not be built here.

The F150 will supposedly have the I4 Ecoboost, 3.7L V6, 3.5L Ecoboost, 5.0 V8, and 4.4L Diesel. Basically, a flavor for every buyer.

Until we see what Ecoboost can do........... everything we say is just speculation. Our first flavor of it will be in the Lincoln MKS.

 

It's pretty obvious a lot of you haven't driven a newer turbo-4, like a LNF, subaru 2.5L, or the acura RDX.......

 

Didn't mean for it to be a "2.3 gas versus 7.3 diesel comparo... I was simply using my 7.3 as reference because I have so much experience with it. I have driven DOZENS of diesels in small and mid-sized cars all over the world too - from 1.8 to 3.6L and all sorts of induction. Overall, my impressions are no jack-rabbit starts, great fuel economy, strong little beasts, very respectable performance.
It is simply my opinion that the diesel cycle is the better choice over a spark-fired Otto cycle for truck applications - disregarding all other factors including displacement, induction, gearing, etc.

Respectfully, I don't refuse to see that fact. I refuse to accept that fact as a viable option for a vehicle to be driven frequently under widely-varied conditions.
Just how often do you run your engine at redline for sustained periods?
I'd rather reach max TQ as close to idle as possible - where my engine typically runs. Peak efficiency is at peak RPM - keep it where it can be useable.

Again, you are trying to overcome a "shortcoming" of an inferior engine application through use and modification of more peripherals like transmission, gearing, converters, etc. to achieve the final wheel-torque you are after. I prefer the better solution for the powerplant coupled with more basic and simple peripherals to do the same job. EVERY improvement you can offer for the gasser can also be used for the diesel...period... making it even more economical and useful as well.

In other words - a screwdriver CAN be a decent chisel, prybar, or scratch awl too if it just had a little bigger handle, a metal cap on the handle to beat on, and sharper corners... But isn't there a better tool for do those jobs... like an actual scratch awl, a chisel, and a pry bar?

PLEASE UNDERSTAND ME CLEARLY - I have never said that "HP does not count". I have built too many engines for hot rods, cars, trucks, and tractors to even think horsepower is not significant. I want all the HP I can get in my old Muskrats! But when talking TRUCKS, I want torque more than I do HP.

Quick points - The 2.3 TDi Mercedes that I drove on the Autobahn at 145mph sustained was taching well over 4000rpm (nailed against the speed-limiter), and redlined over 5k. Don't be fooled into thinking that new diesels are capable of spinning higher than they used to. Even though the flamefront propagation for diesel is slower than gas, technology has overcome some traditional hurdles that limited diesel rpms. (BTW, my 7.3 has max shift settings at 3800, and redlines at 4k - newer PS units are even higher than mine.)

 

Agree with most everything you say except what is highlighted.
I stated in an earlier post that given Ford's current financial situation, I would seriously consider the costs of developing this I4 Ecoboost engine for a full-sized truck application. Will there be enough sales to justify the development costs and tooling and testing, etc? Then, even if it does meet all those criteria, what will it do to the reputation of the infamous F-150? Is it worth the risk to put an I4 in a 1/2-ton truck just for the VERBAL abuse and mockery alone? Reputations are HARD to earn, and EASY to burn.

 

Part of the point I was making, is that the I4 Ecoboost is not just a F150 item. This basic engine will show up in many different vehicles, and will just be tuned differently based on application.

Thus, you have economies of scale.

BTW, Igor, on BON, said that the 260hp/2.5L that was talked about, is understating horsepower, and overstating size. I guess we will have to see.

 

It's pretty obvious a lot of you haven't driven a newer turbo-diesel, like a 3.0TDi, 2.2L CDi turbo diesel, or the European Focus 1.8TDCi......


Focus 1.6 TDi doing 222kmh (138mph)
Video of Focus TDCi from 0-125mph
Ford Mondeo 2.0 TDCi from 0-120mph


they might not be as fast as turbo-gas units but they are FAR more fuel-friendly. A trade-off many would like to make today. Performance above at 40+mpg is awesome IMO.
Anyone on this board got a Caliber, Focus, or Cobalt with a 1.6L engine they can run 140mph in and get 40+mph? I'm not thinking so.

Not saying they are the cure-all, just asking some to give credit where it's due... nothing more.

 

Sounds more than just plausible.

 

Yes, the LNF equiped 09 Cobalt can. So can the Sky and Solstice with the LNF.

55 mph is 40-44mpg.

So the newer TDIs you listed are not FAR more fuel-friendly. Especially when you take in to effect the cost to do so. I can get my 40+ mpg with 87 octane gasoline. The fuel costs less, the repairs cost less and the car costs less.

So I can go faster, for cheaper.

I challenge anyone who has not driven a LNF powered vehicle to go test drive one. Take it out and set the cruise control at 55mph and look at what the DIC reports for current MPG.

 

Ummm... I'm thinking you are looking at your instantaneous MPG readout while cruising down the highway at 55 without your foot in it or the boost on, am I right?

Let's talk TOTAL MPG over the entire tank - average MPG for the car.
There are threads all over the place with numbers coming out the wazoo.
Average looks to be high-20's to mid-30s in every case.

http://www.cobaltss.net/forums/showthread.php?t=115981
"i average 31 my best 37 with ss/sc stage 2 tune with cold air and 3'' exhaust as stated before stay out of boost tou will get the best milage = no fun"
"I recently hand checked it with some city driving, mainly highway, and 5 passes at a 1/8th mi track and i got 28. With 5 passes, I'm sure atleast one other time I jumped on it, I thought 28 was awesome."
"I just drove from Mayport, FL to Bremerton, WA (roughly 3200 miles). Did it in two days and made about 32 (at an average speed between 75-80) MPG for the entire trip. Now that I'm in town and driving in the city I get about 26-28"
"also...those guys that were saying they can get 50 mpg barely tapping the gas....i can get 99 mpg coasting....so that instantaneous mpg is irrelevent!"

Have yet to see a post where someone averaged over 40mpg on an entire tank - WITH pounding on it to boot.

My challenge is still there for you bro!

 

I'll pipe up. The best tank I've gotten in my Fit is 36.xx. There are a couple wacko crazy hypermilers getting 50+, but they drive like idiots to get those #'s. Most people can knock on ~40mpg taking it easy, light AC use, no loads (passengers, stuff). EPA is 28/34. It's a 1.5l with 100-something hp.

If they offered a diesel, I probably would have bought it.

 

That is a LNJ motor, non-Direct Injection with a supercharger. The LNF is Direct Injected with a turbo.

 

"THAT" is an entire THREAD listed under the 2.0L LNF Performance Tech section of the website and the posters have the cars in their sig.
I took 4 separate quotes from 4 different posts by 4 different people in my prior post.
Do you REALLY want me to start searching with some REAL effort?!?!

Try reading just a little bit more from that link before shooting bullets...



Thanks for the input.

My point with the challenge was to demonstrate that Europe has had really good performers that get well into the 40's for years now. They are not "babying" the throttle or staying out of the boost to squeak-out 40+mpg. The last Mercedes I rented in Germany got FLOGGED by me! Jeebus-Cripes fellas, I am in Germany, in a RENTAL car, on company expense account, with access to the Autobahn, and I'm a car-nut... does ANYONE on this board think I "babied it"?!?! I flogged the sheets out of it guys!!! But also being the car guy, I wanted to see what my $97USD in gas on the AmEx card got me, so I whipped-out the PDA and converted liters to gallons and KMs to miles and whamo... like 41mpg. Trip odo was like 0.7km when we left Munich airport, and the tank was full. Virtually the same with the last Focus I had in Wigan England last year, and the Mondeo I had in Czech Republic, etc.
When we Americans can stop "easing-along" and still get in the 40's... someone has my full 100% undivided attention.

Along with WJH, I have "gone efficient" recently - but done it old-school. I personally am driving a '93-model 4-cylinder with 8 plugs, a 5-spd, and 3.45:1 rear axle and I am averaging 35-38 mpg per tank throughout the year (A/C, heat, gas expanding, contracting, etc). My personal best in the car is a touch over 40mpg achieved with some road driving. No mods, no nothing. Driving sane, no squalled tires, etc. Nope - I can't even race a moped ... don't want to if I can drive by 2 more gas stations!

I have spent lots of seat time in rental cars in Europe - where diesels dominate the market, and I can tell you for sure - they have impressed me. They are way ahead of gas-burners in every-day driving by a mile. Now when we talk trucks... here in the USA... and we are STILL stuck on the gas-thing with a closed-mind, it simply kills me. As for the price difference between diesel and gas... that is purely a fabricated issue meant to get more $ out of the transportation industry IMO. Diesel has been cheaper than gas for decades - even when it was used less. It still is in Europe. So what gives?

Last comment - it is painfully sh1++y that we had cars in the 1970s that would get 28-32mpg without the benefit of radial tires, fuel injection, engine management, and overdrive transmissions, yet we are BRAGGING about 30mpg cars today.
It is sh1++y that we had 35-40 mpg cars in the early 1990s and people are just now trying to hunt them down to use.
And, it is sh1++y that we are even having to go through this whole exercise under pressure and financial diress in the first place... why didn't the market see the need for more economic vehicles simply because it is the right thing to do - instead of because "it costs too much".

Now to even consider something other for an economical TRUCK...

 

That may be in the LNF section, but the quotes you quoted are LNJ motors. Thats the equivalent of posting L98 numbers for a LT1.

As per your post:

A SS/SC is a Cobalt SS supercharged with a LNJ motor. There are no stage 2 tunes for the LNF, only the LNJ.


First off, this person does not have a sig so the car is unknown. Second, he was traveling at an average speed of 75-80mph to get 32mpg average. Thats 20 to 25 mph faster than what I stated.

As per my post:


Again, another LNJ motor, which you left half of their info out of your quote. Not a LNF. Stage 2 and a 2.9" supercharger pulley = LNJ.

Most of the people in that post do not have LNF cars. The LNF Cobalts have only been out for a month.


Please do because you quoted two LNJ motors and one unkown traveling at 80mph.



If you want to read something here is one for you.

http://www.solsticeforum.com/forum/f...oh-yeah-47733/



Again, I still put out the challenge in my original post:


Stop trying to tell me what a car I drive 80 miles every week day will do because you are reading it on an internet forum (and quoting the wrong engine btw). Go out to your local Saturn or Pontiac dealer and test drive a manual redline or GXP @ 55 mph with cruise and let me know what you find. You will be very surprised.

Real world > teh internets